The subject matter disclosed herein relates to thermal power plants and, more particularly, exhaust treatment systems for turbine engines.
Various combustion systems, such as gas turbine engines, combust a mixture of air and fuel to produce hot combustion gases. These combustion gases include various emissions, such as nitrogen oxides (NOx), carbon monoxide (CO), sulfur oxides (SOx), and unburnt hydrocarbons. In general, it is desirable to lower the concentration of these emissions in the exhaust gas. For example, a catalyst may be used to increase a rate of a chemical reaction to convert these emissions into more desirable components. However, the catalyst may be less efficient at lower temperatures, such as during startup of the combustion system (e.g., gas turbine engine). As a result, during these periods of lower temperature (e.g., startup), the exhaust may have higher concentrations of the emissions. In general, regulatory standards create pressure to reduce emissions during off-design conditions such as start-ups and shut downs.